All-solid-state secondary battery including anode active material alloyable with lithium and method of charging the same

Abstract

An all-solid-state secondary battery including: a cathode including a cathode active material layer; an anode including an anode current collector, and an anode active material layer on the anode current collector, wherein the anode active material layer includes an anode active material which is alloyable with lithium or forms a compound with lithium; and a solid electrolyte layer between the cathode and the anode, wherein a ratio of an initial charge capacity (b) of the anode active material layer to an initial charge capacity (a) of the cathode active material layer satisfies a condition of Equation 1: 0.01<(b/a)<0.5, wherein a is the initial charge capacity of the cathode active material layer determined from a first open circuit voltage to a maximum charging voltage, and b is the initial charge capacity of the anode active material layer determined from a second open circuit voltage to 0.01 volts vs. Li/Li + .

What is claimed is: 
     
       1. An all-solid-state secondary battery comprising:
 a cathode comprising a cathode active material layer; 
 an anode comprising
 an anode current collector, and 
 an anode active material layer on the anode current collector; and 
 
 a solid electrolyte layer between the cathode and the anode, 
 wherein the anode active material layer comprises an anode active material and a binder, wherein the anode active material comprises amorphous carbon and at least one of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof, 
 wherein the anode current collector, the anode active material layer, and a region therebetween are Li-free regions at an initial state of or after discharge of the all-solid-state secondary battery, 
 wherein a metal layer is between the anode current collector and the solid electrolyte after the all-solid-state secondary battery is charged, and the metal layer comprises at least one of lithium or a lithium alloy. 
 
     
     
       2. The all-solid-state secondary battery of  claim 1 , wherein a ratio of an initial charge capacity of the anode active material layer to an initial charge capacity of the cathode active material layer satisfies Equation 1:
   0.01<( b/a )<0.5  Equation 1
 
 
       wherein a is the initial charge capacity of the cathode active material layer, determined from a first open circuit voltage to a maximum charging voltage vs. Li/Li + , and
 wherein b is the initial charge capacity of the anode active material layer, determined from a second open circuit voltage to 0.01 Volts vs. Li/Li + . 
 
     
     
       3. The all-solid-state secondary battery of  claim 1 , wherein an amount of the binder ranges from about 0.3 weight percent to about 15 weight percent, based on a total weight of the anode active material. 
     
     
       4. The all-solid-state secondary battery of  claim 1 , wherein the anode active material layer has a thickness of about 1 micrometer to about 20 micrometers. 
     
     
       5. The all-solid-state secondary battery of  claim 1 , wherein the anode active material is in a form of a particle, and wherein the anode active material has an average particle diameter of about 4 micrometers or less. 
     
     
       6. The all-solid-state secondary battery of  claim 1 , wherein the anode active material comprises a mixture of a first particle comprising the amorphous carbon and a second particle comprising the at least one of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, or zinc, and
 wherein an amount of the second particle is about 8 weight percent to about 60 weight percent, based on a total weight of the mixture. 
 
     
     
       7. The all-solid-state secondary battery of  claim 1 , further comprising a plating layer on the anode current collector, the plating layer comprising an element which is alloyable with lithium,
 wherein the plating layer is between the anode current collector and the anode active material layer. 
 
     
     
       8. The all-solid-state secondary battery of  claim 7 , wherein the plating layer comprises at least one of gold, silver, zinc, tin, indium, silicon, aluminum, or bismuth. 
     
     
       9. The all-solid-state secondary battery of  claim 7 , wherein the plating layer has a thickness of about 1 nanometer to about 500 nanometers. 
     
     
       10. The all-solid-state secondary battery of  claim 1 , the metal layer is between the anode current collector and the anode active material layer. 
     
     
       11. The all-solid-state secondary battery of  claim 7 , wherein the metal layer is disposed within the anode active material layer, between the anode active material layer and the anode current collector, between the plating layer and the anode current collector, between the plating layer and the anode active material layer, or a combination thereof. 
     
     
       12. The all-solid-state secondary battery of  claim 1 , wherein the metal layer has a thickness of about 1 micrometer to about 200 micrometers. 
     
     
       13. The all-solid-state secondary battery of  claim 1 , wherein the cathode active material layer further comprises a solid electrolyte. 
     
     
       14. The all-solid-state secondary battery of  claim 13 , wherein an amount of the solid electrolyte ranges from about 1 weight percent to about 50 weight percent, based on a total weight of the cathode active material layer. 
     
     
       15. The all-solid-state secondary battery of  claim 1 , wherein the all-solid-state secondary battery is a lithium battery. 
     
     
       16. The all-solid-state secondary battery of  claim 1 , wherein the maximum charging voltage is about 3 volts to about 5 volts versus Li/Li + . 
     
     
       17. The all-solid-state secondary battery of  claim 16 , wherein the maximum charging voltage is about 4.2 volts to about 5 volts versus Li/Li + . 
     
     
       18. The all-solid-state secondary battery of  claim 1 , wherein
 the anode current collector comprises a material that does not form a compound with lithium. 
 
     
     
       19. The all-solid-state secondary battery of  claim 18 , wherein the anode current collector comprises at least one of titanium, copper, iron, cobalt, or nickel. 
     
     
       20. An all-solid-state secondary battery comprising:
 a cathode; 
 an anode; and 
 a solid electrolyte layer, 
 wherein the cathode comprises a cathode active material layer, 
 wherein the anode comprises an anode current collector and an anode active material layer on a surface of the anode current collector, wherein the anode active material layer comprises a binder and an anode active material comprising amorphous carbon, 
 wherein the solid electrolyte layer is between the cathode active material layer and the anode active material layer, 
 wherein the anode current collector, the anode active material layer, and a region therebetween are Li-free regions at an initial state of or after discharge of the all-solid-state secondary battery, and 
 wherein a metal layer is between the anode current collector and the solid electrolyte after the all-solid-state secondary battery is charged, the metal layer comprises at least one of lithium or a lithium alloy. 
 
     
     
       21. The all-solid-state secondary battery of  claim 20 , wherein the amorphous carbon comprises at least one of furnace black, acetylene black, Ketjen black, or graphene. 
     
     
       22. The all-solid-state secondary battery of  claim 20 , wherein the amorphous carbon is in the form of a particle and has an average particle diameter D50 of about 4 micrometers or less. 
     
     
       23. The all-solid-state secondary battery of  claim 20 , wherein the anode active material further comprises a second particle. 
     
     
       24. The all-solid-state secondary battery of  claim 23 , wherein a weight ratio of the amorphous carbon to the second particle is about 20:1 to about 1:2. 
     
     
       25. The all-solid-state secondary battery of  claim 23 , wherein the second particle comprises at least one of platinum, silicon, silver, tin, or zinc. 
     
     
       26. The all-solid-state secondary battery of  claim 23 , wherein the second particle comprises at least one of silver, tin, or zinc. 
     
     
       27. The all-solid-state secondary battery of  claim 20 , wherein the binder comprises at least one of styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, or polyethylene. 
     
     
       28. The all-solid-state secondary battery of  claim 20 , further comprising a film disposed on the anode current collector and between the anode current collector and the anode active material layer, the film comprising lithium or an element alloyable with lithium. 
     
     
       29. The all-solid-state secondary battery of  claim 20 ,
 wherein a ratio of an initial charge capacity of the anode active material layer to an initial charge capacity of the cathode active material layer satisfies Equation 1:
   0.01<( b/a )<0.5  Equation 1
 
 
 
       wherein a is the initial charge capacity of the cathode active material layer, determined from a first open circuit voltage to a maximum charging voltage vs. Li/Li + , and wherein b is the initial charge capacity of the anode active material layer, determined from a second open circuit voltage to 0.01 volts vs. Li/Li + . 
     
     
       30. The all-solid-state secondary battery of  claim 29 , wherein the ratio of the initial charge capacity of the anode active material layer to the initial charge capacity of the cathode active material layer satisfies a condition of Equation 1A:
   0.01<( b/a )<0.25.  Equation 1A
 
 
     
     
       31. The all-solid-state secondary battery of  claim 29 , wherein the ratio of the initial charge capacity of the anode active material layer to the initial charge capacity of the cathode active material layer satisfies a condition of Equation 1B:
   0.01<( b/a )<0.2.  Equation 1B
 
 
     
     
       32. The all-solid-state secondary battery of  claim 29 , wherein the ratio of the initial charge capacity of the anode active material layer to the initial charge capacity of the cathode active material layer satisfies a condition of Equation 1C:
   0.01<( b/a )<0.1.  Equation 1C
 
 
     
     
       33. A method of charging an all-solid-state secondary battery, the method comprising:
 charging the all-solid-state secondary battery of  claim 1 , 
 wherein the initial charge capacity of the anode active material layer is exceeded. 
 
     
     
       34. The method of  claim 33 , wherein a charge capacity of the all-solid-state secondary battery is about two times to about 100 times greater than an initial charge capacity of the anode active material layer. 
     
     
       35. The method of  claim 33 , wherein when the initial charge capacity of the anode active material layer is exceeded, a metal layer comprising at least one of lithium or a lithium alloy is disposed between the anode current layer and the solid electrolyte layer. 
     
     
       36. An all-solid-state secondary battery comprising:
 a cathode comprising a cathode active material layer; 
 an anode comprising
 an anode current collector, and 
 an anode active material layer on the anode current collector; and 
 
 a solid electrolyte layer between the cathode and the anode, 
 wherein the anode active material layer comprises an anode active material and a binder, wherein the anode active material comprises amorphous carbon and at least one of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc or combination thereof, and 
 a metal layer between the anode active material layer and anode current collector, wherein the metal layer comprises at least one of lithium or a lithium alloy.